Genetic diversity in sewan grass (Lasiurus sindicus Henr.) in the hot arid ecosysystem of Thar Desert of Rajasthan, India

Abstract

Sewan grass (Lasiums sindicus Henr.), considered as the "King of Desert Grasses", is a dominant grass species of hot arid ecosystem of Great Indian Desert, covering Western Rajasthan and parts of Pakistan. This grass is extremely drought resistant and thrives even in areas receiving very tow rainfall (100 to 150 mm) annually under extreme temperatures ranging from -3 to 50 °C. The present study was undertaken to analyze the extent of geneticvariability existing among the L. sindicus germplasm collected from Bikaner, Batmer and Jaisalmer, the diversity rich districts of hyper-Arid Rajasthan, using ISSR and RAPD markers. Methodology Twenty seven genotypes of L sindicus were collected from Jaisalmer (10 accessions), Batmer (9 accessions) and Bikaner (7 accessions) and 1 old collection maintained at CAZRI. Jodhpur, Rajasthan was used in this study. Atotal of 18 RAPD and 14 ISSR markers were screened of which 12 RAPD and 10 ISSR primers amplified distinct and scorable fragments. Data analysis was performed using NTSYS-pc, SIMQUAL, Genalex 6.5 and POPGENE version 1.32 programs, and dendrograms were generated using unweighted pair group method fa arithmeticmean (UPGMA). Results The comparative analysis of data showed that RAPD makers were better than ISSR with regard to polymorphism detection, as they detected 90% polymorphism in comparison to 74% for ISSR markers. The values of average number of polymorphic fragments per assay, polymorphism information content (PIC) and dscriminatory power (Dj) were more for RAPD (5.83, 0.222 and 0.78 respectively) than for ISSR (5.7, 0.138 and 0.605 respectively) markers. The UPGMA clustering was not conspicuous under the influence of high within region diversity, however, accessions collected from same region tended to cluster together. Genetic similarity values obtained from Jaccard's coefficient using combined data of both the marker systems were between 0.58and 0.74. Interpretation The results indicated the existence of wide genetic variability within and among regions in this species which can be used for germplasm conservation and improvement.